The problem is that the format of schools has very little to do with educating students, and quite a lot to do with babysitting while parents are at work. Keeping the kids at home rather laid this bare.
All studies suggest that a highly trained adult (multiple post-grad degrees and years of experience and training) can engage in creative learning for perhaps 4 hours in a day, split into 3-4 separate periods. For untrained children, it is likely that, in ideal circumstances, at best, they can realistically manage an hour and a half split into two or three fairly short sessions, starting no earlier than 11am so the kids are well-rested and ready for some actual work. Lecturing from the blackboard starting at 08:30 is possibly the worst method of delivering learning, and schools appear to willfully go against any academic advice on how best to improve educational outcomes.
Ultimately, you could probably achieve better learning outcomes keeping the kids at home and engaging in maybe 2 hours of well-crafted, engaging educational content a day. Trying to replicate school's failed 8-hour model at home was doomed to fail, but the problem wasn't to do with tech or hybridization - the content is the issue and however you choose to deliver it it's been failing the majority of pupils for decades.